In the field of biometric sensing, the use of fingerprints has evolved to be one of the most widely used technologies. This fact can be illustrated and exemplified by considering the field of mobile communication technology, e.g. the use of intelligent mobile devices such as smartphones. In this field there is an increased demand for providing increased security for accessing the devices themselves and also for providing secure access to remote services such as banking services that are available via data communication networks.
In order to enable such secure access by way of fingerprint sensing, a user has to take part in a so-called enrolment procedure where information directly connected to a user's fingerprint is registered for later use in a verification procedure when actual access is to be determined. During such an enrolment procedure, the user is typically prompted to apply a finger to a fingerprint sensor several times until a complete fingerprint, or at least a large part of a fingerprint, has been recorded.
Examples of prior art fingerprint enrolment are described in US patent application publications 2014/0003677 and 2014/0003679. In the systems described in these publications, during the enrolment procedure, a user is provided with feedback in the form of information that tells the user which part of the fingerprint that is still to be recorded.
However, there are drawbacks with prior art enrolment procedures. For example, previous known enrolment methods, including the systems described in the publications cited above, typically apply generalized enrollment schemes aiming to enroll the same fingerprint area for all users, without taking into account what is feeling natural and convenient for the user who is to enroll a fingerprint. These approaches are thus sub-optimal as they, for some users, guide the users to enroll a part of their fingerprint which they will never use for subsequent verification procedures. Such prior art methods and systems typically suffer from a fairly large number of false rejections during verification procedures because a user by instinct might use another part of the fingerprint for verification than the part of the fingerprint that the user was instructed to use during the enrolment.